gasitman

I am really wanting to do a level kit but I get mixed answers, so here goes? I have been told to go with the D25's, but some say they are too soft, and I should go with the revtek spacers and keep the stock springs. I have heard I will need to upgrade some of the steering components. Some say they can put 35's on a '02 with just the level kit, some say no. I will be getting some 17x10 chrome wheels. Oh and the bigest thing is that I cannot get the BFG, or Toyo's in a 33-70-17, only 35-70-17. What am I going to do? Least expensive of course.

Dr. Evil

These are supposed to be a little stiffer than the D25's:

http://customsuspension.com/store/pr...roducts_id=753

Cowhand

Are you sure? I was under the impression that the Custom coils are the same spring rate as stock. The D25's are stiffer than stock.....

Try these guys.....they did my coils with a softer spring rate, and I'm very happy with them. I got another quote from them for a 7" coil with a 350 lb spring rate, and the cost was less than $300 for the pair....

http://www.coilsprings.com/

Dr. Evil

Cowhand,

I mentioned these coils to someone else on another forum...when he talked to custom suspension he was told that they are stiffer than the stock coils (custom suspension uses 1 inch thick wire)....so at this point, I guess its just hearsay and nothing is confirmed...I shouldnt have said anything.....

I was under the impression (from other members on this site) that the D25's were softer than stock (not stiffer)....

I think just about any coil would be better than a spacer.

smokeyram

I put the D25s on to get rid of the spongy ride, as well as level the truck.
As of yet, I have no complaints , they ride pretty firm, firmer than the stockers anyway.
I still need t o swap out the shocks, but so far so goo for the ride quality.

ps, they even feel nice and tight with the plow on, so Im happy

BarryG

You should check out this place. www.koreperformance.com Top quality stuff. He has a variety of suspension levels/options as well as just a leveling kit. Definitely worth a call and they are made specifically for our trucks.

BigBlue

I was always told the D25's are stiffer than stock.

Cowhand

IIRC, the spring rate has more to do with the space between the coils than the diameter of the wire. My softer CSS coils are 1" wire, vs. a way smaller dia. wire on my old SJ coils. The spcing between the coils on my new set is about half what the SJ coils are.

Cowhand

Coil Spring Specialties does (or at least did) the coils for KORE.....and yes, it is top quality stuff.

Sea Bass

Mine seems much stiffer than stock. My truck would bottom out quite easily in the front before and I haven't been able to bottom out with the d25's yet..... and I've tried.

P.O.R.

i have the D25's,they sure feel stiffer than stock, also hold up great to the weight of my 900# snowplow that hangs of the front,the 25's don't give much with the plow hanging,i'am happy with them...

HOHN

The D25s are stiffer than stock



Notice how the coils have a lot of space between them. This is partly why 1) they are stiff and 2) they will sag.

A properly designed coil spring will be VERY close to coil bind when the axle is into the bump stops.

When the windings are farther apart, you can use thinner wire to produce a given spring rate. This is because there is less "leverage" acting on each individual winding. The spring rate will be the same, BUT there is a drawback to making springs using this cheaper way.

First, it makes the spring weaker for a given spring rate. Since there's less metal to absorb the fatigue, the spring is under more stress doing the same work. This means it will fatigue sooner and worse. My D25s have already sagged a slight amount (about half an inch) used almost always on paved roads with no towing-- and no plow or heavy bumper.

There is something called a "set height"-- which is the point where the springs will NOT return to their original length (or height, in this case). Everything has an elastic limit; you can bend it to a certain extent and it will return to its original shape. If you exceed this limit, you will have a permanent deformity. This is what "set height" is-- how far the spring can be compressed and still return to it's original positions or shape.

Now we'll introduce a term called "solid height", or "coil bind" as we often know it. This is the point were the spring's coils are touching each other and it cannot be compressed farther. It's "solid".

You want your coil spring to have a little room left over when the suspension is fully bottomed out-- so your "solid height" needs to be shorter than the length of the spring when the suspension is bottomed. Otherwise, the spring will bottom out before the axle hits the bumpstops.

Using what we know about set height and solid height, we can see that we want a spring with the following qualities:

1) "Solid height" should be just a hair shorter than the length of the spring when the suspension is bottomed out hard-- meaning the bumpstops are FULLY compressed.

2) The "set height" should ALSO be just a hair shorter than the length of the spring when fully bottomed out. This ensures that the spring will return to its proper height even after a hard bottom. "Set height" and "solid height" should be very close to each other.


And now we see why the D25s are such cheap springs. First-- they are sold by SJ as part of a lift kit that includes longer bump stops. Why? This is to REDUCE suspension travel. This is necessary because the springs have a pretty high "set height" and they can't be compressed as much as the stockers and still return to their full height. Remember, fewer windings means that each individual coil has to deflect farther for a given amount of suspension movement.

Consider this example: two springs, identical height of 30 inches. One has 10 coils, the other has 15 coils. Now compress BOTH of these springs to a height of 20 inches.

On one spring, each winding only had to compress a little because the movement of 10 inches is shared over 15 coils. Thus, each coil only deflects 2/3"

On the cheaper spring, each of the 10 coils has to share the movement of 10 inches of compression-- meaning each coil carried 1 full inch of movement.

Not only is the spring with fewer winding under more stress because there are fewer coils, but the spring wire MUST be thinner with the fewer coils to give a certain spring rate. Thus, our above example would have 33% MORE stress per coil winding-- and each winding is THINNER!!!!!

When you account for the thickness, the D25 style spring (a cheapie) could have 50% or MORE stress on it at any given time relative to the beefier spring. Since all steel fatigues eventually, this increased stress rapidly increases the rate at which the springs fatigue.

Compare this to a beefy coil like the KORE coils, and you will see that the big coils not only ride better for a given weight capacity, but they will not limit suspension travel, and they will last MUCH MUCH longer.

I like the levelled front end of my truck, but buying the D25s was a mistake. LEARN FROM ME-- BUY THE KORE COILS!!!!

Jlh

P.O.R.

how much are the kore coils,and do they level the truck without any other parts,other than shocks of course.

HOHN

IIRC, the KORE coils are on the order of $320/pr. Call Kent, as he will sell you anything from a full kit to only springs.

Yes, they will level the truck with no other mods needed. You should look at your track bar when doing this as the high ride height will aggravate any play in the front end.

jlh

Fred Swanson

You can't go wrong with the KORE leveling kit. Last time I checked, KORE does not sell individual pieces of systems.
The leveling kit is an excellent product, and all pieces are guaranteed for life. The ride comparison is superb compared to other lift kits out there now.
Add to it the sway-bar drop brackets, and you have a well mannered truck that will perform very well.
Their PACE system is an excellent deal, too.
I installed one on a guys 2001 last night, and he was very happy with the ride. We were hitting big speed bumps at regular speed and then up to 40MPH, and the truck responded beautifully, and under control, not bucking and jumping.